New pixel time offsets and cycle times

[alessandrofelder]

This PR will handle differences between LabView versions in storing/computing pixel time offsets and cycle time.

[ageorgou]

Once the above changes are made, it would be good to compare with the existing analysis code if possible.

There are other possible improvements but better left for another round, since this is already quite a lot! For example:

• Try compressing the pixel data, either in the same way as the manifold and image data, or through a method of the new class (ideally, only store the row offsets and the dwell time, and have a method that computes the full array).

• Use a "factory method" for creating an LabViewTimings of the right subclass.

• How we check for pointing mode in LabViewTimings

• The interface of LabViewTimings (is a dict acceptable, or should we have a method for getting the values for a particular ROI?) This may particularly help with...

• How we refer to ROIs, especially when we retrieve the timings for them (improve the temporary solution from 661aca6ec4cb91cc4bbf7b1913569dff34df2eb2)

• How we build up the offsets array in LabViewTimings231 (as commented in the review)

• The location of the test input files: now that we have a lot of them, should we put them in separate folders?

• AF Edit: as mentioned in one of the @ageorgou 's comments above, it would also be good to avoid a loop over all cycles in timings.py if possible. Noting here so everything is in one place.